1. Field of the Invention
This invention relates to apparatus using elements which interact with one another, and more particularly to apparatus using lattice arrays of interactive elements where the positions of the elements within the lattice are substantially determined by the interactive forces existing between the elements.
2. Description of the Prior Art
In the past, various systems have been described using elemnts which have the capability of interacting with one another. For instance, cylindrical magnetic bubble domains have stray magnetic fields which cause interactive forces to exist between bubble domains which are sufficiently close that the stray magnetic fields of each couple to one another. U.S. Pat. Nos. 3,689,902 and 3,701,125 describe magnetic bubble domain systems in which the functions of memory, storage, decoding, writing, and reading are described. These prior art systems are usually designed so that interactions between bubble domains are minimized. Since interactions can lead to adverse deflection of the bubbles, such a design has always been considered advantageous. Also, these prior systems used defined structures for determining the path of all bubble domains in the system. Generally, these prior systems are characterized by information storage in the form of the presence and absence of magnetic bubble domains.
Recently, there has been some work in magnetic bubble domain technology using information which is coded by other than the presence and absence of magnetic bubble domains. For instance, copending application Ser. No. 319,130, filed Dec. 29, 1972, describes a magnetic bubble domain apparatus in which different size magnetic bubble domains provide the various information states. In this manner, all bit positions of the system can be filled, the size of the domain at each position determining the information state of that position. In that copending application, functions such as writing, storage, and reading of the information states are described.
Another apparatus using magnetic bubble domains which have different properties is described in copending application Ser. No. 375,285, filed June 29, 1973. This copending application utilizes different vertical Bloch line configurations for domain wall magnetization in order to code magnetic bubble domains in accordance with their properties in a magnetic field tending to collapse the domains. It has been discovered that the field at which a bubble domain collapses is a function of the number of vertical Bloch lines in its domain wall; therefore, various logic states can be provided by domains which have differing numbers of vertical Bloch lines in the domain walls. Of course, this leads to levels of logic higher than merely binary levels.
Still another bubble domain apparatus using bubble domains having different properties is shown in copending application Ser. No. 375,289, filed June 29, 1973. This copending application codes the magnetic bubble domains in terms of their properties of movement in a gradient magnetic field normal to the plane of the medium in which they exist. Depending upon the angle through which these domains are deflected, various information levels can be provided.
A still further technique for coding magnetic bubble domains is described in the IBM Technical Disclosure Bulletin, Vol. 13, No. 10, March 1971, at page 3021. In this publication, G. R. Henry describes coding in terms of the chirality of wall magnetization of bubble domains. A technique for reading different chiral states uses a reference domain into which an unknown domain is forced, leading to a collision which determines the chiral state of the unknown domain.
While the prior art has addressed various aspects of magnetic bubble domain technology, and information storage in general, very little emphasis has been placed on the provision of systems which would have ultimate density configurations, be very stable, and be as structureless as possible. Thus, the prior art has attempted to obtain high densities by, for instance, using smaller and smaller magnetic bubble domains, and by reducing the line width of structures used to move these domains (for instance, electron beam technology has been used to make smaller T and I permalloy overlay bars). However, the prior art has not attempted to divert from established procedures in an attempt to find new approaches which may lead to significant improvements in system performance and in packing density.
The present invention is directed to an entirely new approach for providing apparatus which has a high degree of stability, significantly increased storage densities, and a minimum of structural requirements. In the present invention, a lattice of interactive elements is utilized where the positions of the interactive elements with respect to one another are largely determined by the forces existing between the elements, rather than by the locations of structures used to move the interactive elements. This leads to extremely high density, which can be varied easily, and to structureless arrays of elements having great internal stability. The interactive elements are any elements which can have positions determined by forces existing between them, and are particularly exemplified by magnetic elements such as cylindrical bubble domains. Various means are used to manipulate the interactive elements into and out of the lattice as well as within the lattice array. If desired, information can be coded in the elements within the array, thus providing an extremely high density, structureless storage having internal stability over a wide range of operating conditions.
The existence of arrays of interactive magnetic bubble domains has been shown in the prior art. For instance, the following technical publications describe some of the physical characteristics of bubble domain lattice arrays.
1. S. H. Charap et al, "Behavior of Circular Domains in GdIG", IEEE Transactions on Magnetics, Vol. Mag-5, No. 3, September 1969, page 566. PA1 2. J. A. Cape et al, "Magnetic Bubble Domain Interactions", Solid State Communications, Vol. 8, pages 1303-1306, 1970. PA1 3. W. F. Druyvesteyn et al, "Calculations on Some Periodic Magnetic Domain Sturctures; Consequences for Bubble Devices", Philips Research Reports, Vol. 26, No. 1, pages 11-28, February 1971. PA1 4. J. W. F. Dorleijn et al, "Repulsive Interactions Between Magnetic Bubbles: Consequences for Bubble Devices", IEEE Transactions on Magnetics, Vol. Mag-7, No. 3, page 355, September 1971. PA1 5. F. A. DeJonge et al, "Bubble Lattices", American Institute of Physics Proceedings of 17th Annual Conference on Magnetism and Magnetic Materials, Chicago, Illinois, 1971, Section 4, page 130.
Even though others have studied the various theories and physical properties of lattices containing magnetic bubble domains, no one has heretofore thought of utilizing such lattices in practical systems. Thus, these articles contain no suggestion or statement directed to a usable system incorporating the many features which can be present in lattice arrays of interactive elements. Despite the known existence of lattices of various elements, it remained for the present inventors to recognize that many features can be obtained by the use of lattice arrays to provice apparatus and systems having numerous advantages over those found in the prior art. Rather than utilize known directions for providing storage and memory systems, the present inventors have taken a fresh approach and have obtained systems which are significantly improved over those of the prior art.
Accordingly, it is a primary object of the present invention to provide techniques for very high density storage of information.
It is another object of this invention to provide storage of information in accordance with natural interactive phenomenon, rather than by imposed limitations due to auxiliary structure.
It is still another object of this invention to provide information handling apparatus using arrays of elements whose positions are substantially determined by interactions existing therebetween.
It is a further object of this invention to provide an apparatus which requires only a minimum of structural elements.
It is a still further object of this invention to provide a system for storing magnetic bubble domains with extremely high density.
It is another object of this invention to provide systems using lattice arrays of magnetic bubble domains.
It is still another object of this invention to provide apparatus utilizing arrays of interactive magnetic elements.
It is a further object of this invention to provide storage and memory with extremely high density using interaction between magnetic elements for determination of storage positions.
It is a still further object of this invention to provide techniques for storage of information at very high densities with minimum cost.
It is another object of this invention to provide techniques for high density confinement of interactive elements with high degrees of inherent stability.
It is another object of this invention to provide apparatus having high density storage where operating margins are significantly enhanced.
It is still another object of this invention to provide storage of information which achieves high density without constraints due to auxiliary structure.
It is a still further object of this invention to provide information storage using lattice arrays of coded elements whose positions are substantially determined by interactive forces existing between the elements.
It is still another object of this invention to provide techniques for utilizing arrays of interactive elements in new ways.
It is a further object of this invention to provide apparatus for moving a plurality of interactive elements whose positions are determined by interactions existing between the elements.
It is another object of this invention to provide techniques for accessing interactive elements within lattice arrays.
It is still another object of this invention to provide techniques for controllably moving interactive elements into and out of lattice arrays of such elements.
It is a further object of this invention to utilize multiple lattice arrays of interactive elements.
It is a further object of this invention to provide displays using lattice arrays of interactive elements.
It is another object of this invention to provide interacting elements in confined arrays which have information associated with them.